We have added an optical potential to a conventional Time-averaged Orbiting Potential (TOP) trap to create a highly anisotropic hybrid trap for ultracold atoms. Axial confinement is provided by the optical potential; the maximum frequency currently obtainable in this direction is 2.2 kHz for rubidium. The radial confinement is independently controlled by the magnetic trap and can be a factor of 700 times smaller than in the axial direction. This large anisotropy is more than sufficient to confine condensates with ∼ 10 5 atoms in a Quasi-2D (Q2D) regime, and we have verified this by measuring a change in the free expansion of the condensate; our results agree with a variational model.
We have observed a superfluid gyroscope effect in a dilute gas Bose-Einstein condensate. A condensate with a vortex possesses a single quantum of angular momentum and this causes the plane of oscillation of the scissors mode to precess around the vortex line. We have measured the precession rate of the scissors oscillation. From this we deduced the angular momentum associated with the vortex line and found a value close toh per particle, as predicted for a superfluid.
Julian received is PhD from Virginia Tech in Engineering Mechanics in 2007. He spent a semester teaching at community college in the area and then spent two years at University of Massachusetts continuing his research in finite element modeling and biomechanics and continuing to teach. In 2010, he began his current tenure track position at the University of Southern Indiana. Over the past several years, the commercial finite element software industry has seen significant growth in both capability and reach. As such, today's undergraduate students have access to sophisticated, yet easy to use simulation tools. For better or worse, use of the tools themselves requires neither an understanding of foundational principles nor a working knowledge of the finite element method. One could make the case that this is part of the natural evolution of any new tool (as one no longer needs to be a mechanic to drive a car). On the other hand, users absolutely need to know enough to understand the consequences of their own modeling choices (e.g. how boundary conditions are applied, element selection, meshes size, etc.). Thus, the proliferation of FEA software in industry (1) necessitates treatment of these tools at the undergraduate level and (2) suggests a balance be struck between the software and theory in these courses.This paper details the authors' experience with a first course in finite element analysis within an undergraduate only engineering curriculum. In particular, the struggle to find the best balance between FEA theory and practical use of software is discussed. Within the course, students complete a variety of assignments using a mixture of resources to include hand calculations, Matlab by Mathworks, and Dassault Systeme's SolidWorks. The course culminates in a self-selected student project requiring they assess the impact of modeling choices on results of particular interest.One important finding is the limitations of some commercial packages in developing one dimensional models, an important stepping stone to understanding of FEA theory. In addition, the paper studies the impact of prior programming experience on a student's ability to succeed in the course. Finally, the authors have experimented with a course textbook which emphasizes use of software and alternatively, a text with more comprehensive treatment of FEA fundamentals.
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